1,3-苯二偶氮-5,5′-双罗丹宁与钯显色反应的研究及应用

Study and Application of the Color Reaction of New Reagent 1,3-diazobenzyl-5,5′-bisrhodanine with Palladium

合成并研究了一种新显色剂1,3-苯二偶氮-5,5′-双罗丹宁与钯的显色反应,建立了测定钯的新方法。在非离子表面活性剂Triton X-100存在下,于pH=4.7的HAc-NaAc缓冲溶液中,试剂可与钯（Ⅱ）生成橙红色络合物,络合比为2∶1,最大吸收波长为525 nm,表观摩尔吸收系数ε=8.3×104L/mol.cm。当钯浓度在0~30μg/25mL范围内时符合比耳定律。该方法应用于钯碳催化剂中钯的测定,操作简便且选择性好,结果满意。

A new reagent 1,3-diazobenzyl-5,5′-bisrhodanine was synthesized and its color reaction with palladium was studied.In the presence of surface active agent of Triton X-100 and pH = 4.7 buffer solution,reagent reacts with Pd（Ⅱ） to form a stable orange-red complex（2 ∶ 1） with maximum absorption at 525 nm.Beer′s law is obeyed for Pd（Ⅱ） in the rang of 0 ～ 30 μg / 25 mL.Its apparent molar absorptivity is 8.3 × 104 L.mol-1.cm-1.The method is simple and rapid and has the good selection.It has been applied to the determination of palladium in catalysts with satisfying results.